If it is as easy (apparently not Jon otherwise this thread wouldn't be here) as it used to be to 'Deposit to mobile bill' take my advice and don't do it, deposit another way, where you pay for your casino credits straightaway, not have them on the 'knock' until your phone bill is due.
A good few years back in my very naive days and I'd just moved into own house, had baby (not me literally
) and was very, very skint despite having a decent job I fell foul of this 'loophole' sites like mbet, mfortune, Wild Jacks Mobile would let you deposit up to £300 PER DAY on your mobile bill (not that I ever went anywhere near this but deadly to say the least)
I'm gonna cut a long story short but I now owe EE (orange at the time) over 2K, my debt and I am paying it but its gonna take a long time and every time I make a payment I think 'You Idiot Jon'